sched: Micro-optimize the smart wake-affine logic
authorPeter Zijlstra <peterz@infradead.org>
Thu, 4 Jul 2013 04:56:46 +0000 (12:56 +0800)
committerIngo Molnar <mingo@kernel.org>
Tue, 23 Jul 2013 10:22:06 +0000 (12:22 +0200)
commit7d9ffa8961482232d964173cccba6e14d2d543b2
tree80fd615fb64b1bd82e0de0e5d1e8be2bae8cb06d
parent62470419e993f8d9d93db0effd3af4296ecb79a5
sched: Micro-optimize the smart wake-affine logic

Smart wake-affine is using node-size as the factor currently, but the overhead
of the mask operation is high.

Thus, this patch introduce the 'sd_llc_size' percpu variable, which will record
the highest cache-share domain size, and make it to be the new factor, in order
to reduce the overhead and make it more reasonable.

Tested-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/51D5008E.6030102@linux.vnet.ibm.com
[ Tidied up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/sched/core.c
kernel/sched/fair.c
kernel/sched/sched.h